Transformer station carried by a mast

ABSTRACT

The invention relates to a transformer station carried by a mast. Such a station comprises a transformer and a high voltage connection device last fastened onto the mast the one above the other. A low voltage connection device is located within the hollow mast. An access device to the high voltage circuit-breaker is provided and comprises a ladder, the lower portion of which is foldable, a footbridge surrounded by a hand rail. The station is remarkable in that it comprises further a safety device hindering the unfolding of the ladder as long as the high voltage line as well as the primary of the transformer has not both been grounded.

United States Patent Comte et al.

TRANSFORMER STATION CARRIED BY A MAST Inventors: Bernard Comte, 1723Marly; Victor Cler, 1700 Fribourg, both of Switzerland Assignee: GramS.A., Broye, Fribourg, Switzerland Filed: Dec. 9, 1971 Appl. No.:206,292

US. Cl. ..174/45 TD, 200/48 R Int. Cl. ..ll01h 31/00 Field of Search..307/149; 174/45 R, 45 TD;-

References Cited UNITED STATES PATENTS l/l957 Storsand ..3l7/18 A [451 7Dec. 19, 1972 Primary Examiner-Robert K. Schaefer AssistantExaminer-William J. Smith Attorney-Irvin S. Thompson et al.

[5 7] ABSTRACT The invention relates to a transformer station carried bya mast. Such a station comprises a transformer and a high voltageconnection device last fastened onto the mast the one above the other. Alow voltage connection device is located within the hollow mast. Anaccess device to the high voltage circuit-breaker is provided andcomprises a ladder, the lower portion of which is foldable, a footbridgesurrounded by a hand rail.

- The station is remarkable in that it comprises further a safety devicehindering the unfolding of the ladder as long as the high voltage lineas well as the primary of the transformer has not both been grounded.

17 Claims, 6 Drawing Figures PATENTED DEC 19 1972 SHEET 2 [IF 3 PATENTEDDE 19 1973 SHEET 3 BF 3 The present invention has for its object atransformer station located on a mast comprising a mast the lower end ofwhich is fastened in a base located within the earth and the upper endof which is provided with a transversal arm receiving the fastenings forthe high tension line. This station comprises further a transformer aswell as a high voltage connection device also carried by the mast,comprising a circuit-breaker for each phase as well as a low voltageconnection device located within the mast in the vicinity of its lowerend. This transformer station comprises at least an access device to thehigh voltage circuit-breaker constituted by a platform, a hand rail anda ladder fixed along the mast and the lower portion of which isfoldable.

This transformer station distinguishes itself by the fact that itcomprises a safety device hindering the unfolding of the lower portionof the ladder before that the two connections of each of the highvoltage circuitbreaker are not grounded.

The attached-drawing shows schematically and by ways example oneembodiment of the transformer station according to the invention.

FIG. 1 is a general elevation view of it.

FIG. 2 is a view from above of the high voltage connection device and ofa part of the access device, the mast being broken.

FIG. 3 is a cross section along line Ill-III of FIG. 2.

FIG. 4 is a perspective view of the lower portion of the mast, thesafety device being in active position.

FIG. 5 is a similar view' to FIG. 4 the safety device being in inactiveposition.

FIG. 6 is a plan view of a detail of a chair carrying the transformer.

The transformer station shown comprises a hollow concrete mast 1 thelower end of which is fastened in a base located within the earth (notshown) whereas the upper end has an arm 2 receiving fastening means of ahigh voltage line 3, 4, 5. A transformer 6 is carried by a chair (shownin detail in FIG. 6) fastened to the mast 1.

The mast l'comprises in one of its lateral faces a modified at will infunction particularly of the dimensions of the transformer 6 that it hasto carry.

This fixing plate 9 carry two supports 12 vertically spaced and betweenwhich are hinged near the ends of the support, two beams constitutedeach by two irons 13, which are parallel and connected at their freeends.

The transformer 6 is led on these two beams the angular position ofwhich is adjusted in function of the width of the base 14 of thetransformer 6. The base of the transformer 6 is fastened onto the chairby means of tie-rods 7 passing through the irons 13 of each beam so thatthe distance separating the transformer from the mast may be very easilyadjusted by simple sliding of the transformer on the beams beforetightening the tierods.

Above the transformer, at a determined distance, is located the highvoltage connection device. This high voltage connection comprises also afixing plate 14 fastened to the mast in the same way as the chair of thetransformer 6 by means of bolts and nuts cooperating with the profile 8sunk in to the body of the mast 1.

This fixing plate 14 comprises a support 15 extending perpendicularly tothe mast 1 above the transformer 6. This support 15 presents atransversal cross section of square shape one of the diagonal of whichis located vertically. This support carries, for each of the phases ofthe high voltage line 3, 4, 5, a circuit-breaker unit comprisingconnecting means to the line and to the transformer as well as a fuse16. In that way each fuse 16 is connected at a high voltage line 3, 4 or5 on the one hand and to a primary connection 17, 18 or 19 of thetransformer on the other hand. These fuses 16 are fastened in removableway by contacting pliers in a a known way.

It is evident that each contacting plier of the fuse 16 as well as theconnection means of the said fuses as well to thehigh voltage lines 3,4, 5 as to the primary connection 17, l8 19 of the transformer 6 areelectrically insulated with respect to the support 15 and thus to themast 1. These pliers are directed towards the mast 1 to facilitate thereplacement of the fuses 16.

The low voltage connection of the secondary of the transformer 6 areconnected by insulated electrical cables passing within the cavity ofthe mast l to a low voltage connection device located in the lowerportion of the mast 1 and to which access is given by a door 20. Thislow voltage connection device is well known and will not be described indetails, insures to connect the low voltage outputs either to aerialline or to underground cable.

It is to be noted that thanks to the disposition and to the conceptionof the high voltage connection device it is easily possible to cross thehigh voltage phases if it is necessary. As a matter of fact theconnectingmeans connecting the fuses 16 to each of the lines 3, 4, 5being disposed in line according to a direction which is parallel to thehigh voltage line 3, 4, 5 and underneath this line, each fuse 16 may beindifferently connected to anyone of the phases 3, 4, 5 of the highvoltage line.

Finally due to the position and the shape of the support 15 all theedges of the high voltage connection device are oblique that is inclinedwith respect to a horizontal direction, which enables a favorable flowof the water avoiding the formation of ice and avoids that the birdscome to rest on the parts constituting the high voltage connectiondevice. This permits to reduce the overall dimensions in an importantway. Finally this disposition leaves three sides of the mast 1 free forthe low voltage aerial output.

It has to be noted further that a hook (now shown) is fastened under thesupport 15 of the high voltage connection device, just underneath thecentral position of the transformer.This hook may be used to rise atransformer by means of a pulley. As the high voltage connection deviceitself is relatively light, the station may be mounted without importantelevating engine.

During the rising of the transformer 6, the beams of the chair arewidened to give free passage, than they are put closer together andpositioned before resting the transformer on this beams.

This transformer station comprises further an access device to enablethe replacement of the fuse cartridges 16. This access device comprisesa footbridge 21 also fastened to the profile 8 sunk into the body of themast 1. This footbridge is-provided with three containers 22 intendedfor the storing of fuse cartridges 16. A hand rail 24 surrounds threesides of the footbridge for the security of the worker. A container 23,fastened to the hand rail contains a hook or plier enabling to a workerlocated on the footbridge 21 to exchange the fuse cartridges 16. I

Finally this access device comprises a ladder 25 fastened along the mast1 to give way to the footbridge 21. This ladder 25 comprises a lowerfoldable portion to hinder the access of the footbridge to noneauthorized persons.

Finally this transformer station comprises further a safety devicehindering the unfolding of the lower part of the ladder, and thus theaccess to the footbridge as long as the two connections of each of thefuse car? tridgesl6 are not grounded.

The safety device comprises a series of metallic double contacts 26, 27,fast with fixing pads 28 surrounding the support but not tightened onthis one, in order to be able to slide along this support. These doublecontacts 26, 27 are equal in number to the number of the fuse cartridges16 and their ends are placed in such a way that they may through alinear displacement along the support, come in abutment against thecontacting parts 29, 30 respectively electrically connected to thecontacting. pliers of the cartridges located on either side of thesecartridges.

In the example shown the three fixing pads28 are fast the one to theothers by a flat-iron 31. One of the fixing pads 28 comprises anextension 32 the free end of which is hinged on the end of a control rod33 the other end of which is hinged in 34 to an eccentric 35. Theeccentric 35'is fastened to the upper end of an actuating rod 36 pivotedin fixed supports on the ladder 25.

The lower end of this actuating rod 36 is provided with a handle 37 forits driving into rotation. This handle 37 is provided on the one handwith a lug 38 provided with a hole and on the other hand with a stop 39having the shape of an arc of circle.

When the double contacts 26, 27 are in the position shown at FIG. 2,that is that these contacts 26, 27 are separated from the correspondingcontact parts 29, 30, the handle 37 is in the position shown at FIG. 5.In this position and if the ladder is folded, the padlock 40 may fix thehandle 37 to a bracket 41 fastened with the foldable ladder.

Even if the worker takes the padlock 40 out, he cannot displace thelower portion of the ladder 25 before he has actuated completely thehandle 37 to the right (FIG. 5) since the stop 39 is otherwise locatedon the way of displacement of the ladder 25.

When the handle has been completely displaced (FIG. 4) the doublecontacts 26, 27 has been displaced by the kinematic connections 36, 35,33, 32 and 28 until they abut against the corresponding connecting parts29, 30. In this position one realizes the simultaneous grounding on theone hand of the high voltage line 3, 4, 5 and on the other hand of theprimary connections 17, 18, l9-of the transformer so that no current isable to be present in the circuit-breaker neither through the highvoltage line nor through induction from the secondary of thetransformer.

The worker can only unfold the ladder 25, and thus step up to thefootbridge, when the precited double grounding has been made and incursthus no danger. In fact if the worker has forgotten to open thecircuitbreakers which are normally provided on the foregoing mast of thehigh voltage line, the circuit-breaker of this part of the line wouldhave been automatically actuated by the short circuit caused by thecontacts 26, 27, the fixing pates 28 and the flat-iron 31.

It is further to be noted that the short-circuit which is thus causeddoes not provoke an excessive current within the parts 26, 27, 28 and 31due to the fact that only the capacitive line current is absorbed inthis linkage.

To ensure a safe grounding the flat-iron 31 is electrically connected bya metallic supple connection directly to the ground of the mast 1.

This safety device is simple but absolutely efficient, the worker havingno possibility to go to the footbridge before the high voltage line aswell as the primary connection of the transformer has been set toground.

In fact even once the worker is inposition on the footbridge it is notpossible to displace the handle 37 and thus the contacts 26, 27 sincethe stop 39 is than in abutment against one step of the ladder 25.

What we claim is:

1. A transformer station on a mast comprising a transformer as well as ahigh voltage'connection device having one circuit-breaker for each phasecarried by the mast and a low voltage connection device located withinthe hollow mast, as well as an access device to the high voltagecircuit-breaker constituted by a footbridge provided with a hand railand a ladder fastened along the mast a lower part of which is foldable,and comprising further a safety device hindering the unfolding of thelower portion of the ladder before the two connections of each highvoltage circuit-breaker has been individually set to ground.

2. Station according to claim 1 in which the high voltage connectiondevice comprises a support, presenting in cross section a non circularshape, fastened by one end on the mast and extending perpendicularlyfrom this mast.

3. Station according to claim 2 in which a high voltage circuit-breakerunit is fastened on said support for each phase of the high voltage lineand that each of these units comprises a removable fuse cartridgefastened in contact pliers located obliquely.

4. Station according to claim 3 in which the safety device comprises anumber of double grounding contacts equal to the number of high voltafuse cartridges; each carried by a fixing pad slidingly mounted on thesupport of the high voltage connection device.

5. Station according to claim 4 in which each of the double contactscooperates with a connection part of the corresponding, circuit-breakerunit, located on either side of the fuse cartridge in order toshort-circuit it.

6. Station according to claim 5 in which the fixing pates carrying thedouble grounding contacts are all fastened the one to the other and bythe fact that they are electrically connected to ground.

7. Station according to claim 6 in which the assembly of the fixing padscarrying the grounding double contacts in connected by a control rod toan eccentric fast with an actuating rod extending along the ladder andpivoted in supports fast with the mast.

l060ll 0424 8. Station according to claim 7 characterized by the factthat the lower end or an actuating rod is provided with a handle as wellas a stop.

9. Station according to claim 8 characterized by the fact that the stopis located on the way of the unfolding of the lower folding portion ofthe ladder as long as the double contacts are not in abutments againstthe corresponding contact parts.

10. Station according to claim 9 in which in unfolded position of theladder, the stop is in abutment against one step of this laddermaintaining positively the double grounding contacts in abutment againstthe corresponding contact parts.

11. Station according to claim 10 in which the safety device compriseslocking means of the ladder in folded position respectively in unfoldedposition.

12. Station according to claim 11 in which these locking means locks thehandle to the ladder in folded position.

13. Station according to one of the preceding claims characterized bythe fact that the support of the high voltage connection device has apolygonal shape in cross section.

14. Station according to claim 13 in which the shape of the crosssection of the support is squared and in which one of the diagonals islocated vertically.

15. Station according to one of the preceding claims characterized bythe fact that the axis of the support of the high voltage connectiondevice extends parallelly to the axis of the high voltage line.

16. Station according to claim 15 characterized by the fact that thesupport of the high voltage connection device comprises a rising hooklocated under the median cartouche.

17. Station according to one of the claims 1 to 12 characterized by thefact that the transformer is carried by a chair fastened to the mast andcomprising two horizontal beams displaceable angularly around verticalaxes.

1. A transformer station on a mast comprising a transformer as well as ahigh voltage connection device having one circuitbreaker for each phasecarried by the mast and a low voltage connection device located withinthe hollow mast, as well as an access device to the high voltagecircuit-breaker constituted by a footbridge provided with a hand railand a ladder fastened along the mast a lower part of which is foldable,and comprising further a safety device hindering the unfolding of thelower portion of the ladder before the two connections of each highvoltage circuit-breaker has been individually set to ground.
 2. Stationaccording to claim 1 in which the high voltage connection devicecomprises a support, presenting in cross section a non circular shape,fastened by one end on the mast and extending perpendicularly from thismast.
 3. Station according to claim 2 in which a high voltagecircuit-breaker unit is fastened on said support for each phase of thehigh voltage line and that each of these units comprises a removablefuse cartridge fastened in contact pliers located obliquely.
 4. Stationaccording to claim 3 in which the safety device comprises a number ofdouble grounding contacts equal to the number of high volta fusecartridges; each carried by a fixing pad slidingly mounted on thesupport of the high voltage connection device.
 5. Station according toclaim 4 in which each of the double contacts cooperates with aconnection part of the corresponding circuit-breaker unit, located oneither side of the fuse cartridge in order to short-circuit it. 6.Station according to claim 5 in which the fixing pates carrying thedouble grounding contacts are all fastened the one to the other and bythe fact that they are electrically connected to ground.
 7. Stationaccording to claim 6 in which the assembly of the fixing pads carryingthe grounding double contacts in connected by a control rod to aneccentric fast with an actuating rod extending along the ladder andpivoted in supports fast with the mast.
 8. Station according to claim 7characterized by the fact that the lower end or an actuating rod isprovided with a handle as well as a stop.
 9. Station according to claim8 characterized by the fact that the stop is located on the way of theunfolding of the lower folding portion of the ladder as long as thedouble contacts are not in abutments against the corresponding contactparts.
 10. Station according to claim 9 in which in unfolded position ofthe ladder, the stop is in abutment against one step of this laddermaintaining positively the double grounding contacts in abutment againstthe corresponding contact parts.
 11. Station according to claim 10 inwhich the safety device comprises locking means of the ladder in foldedposition respectively in unfolded position.
 12. Station according toclaim 11 in which these locking means locks the handle to the ladder infolded position.
 13. Station according to one of the preceding claimscharacterized by the fact that the support of the high voltageconnection device has a polygonal shape in cross section.
 14. Stationaccording to claim 13 in which the shape of the cross section of thesupport is squared and in which one of the diagonals is locatedvertically.
 15. Station according to one of the preceding claimscharacterized by the fact that the axis of the support of the highvoltage connection device extends parallelly to the axis of the highvoltage line.
 16. StatioN according to claim 15 characterized by thefact that the support of the high voltage connection device comprises arising hook located under the median cartouche.
 17. Station according toone of the claims 1 to 12 characterized by the fact that the transformeris carried by a chair fastened to the mast and comprising two horizontalbeams displaceable angularly around vertical axes.